Last



w. A-KRENTLER LAST.

APPLICATION HLED APR- 23; 1919- lAlOA-W; patented Mar. 21,1922.

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UNITED STATES Parser WALTER A. KRENTLER, OF DETROIT, MICHIGAN, ASSIG-NORTO KREN'ILER-ARNOLD HINGE LAST COMPANY, OF DETROIT, MICHIGAN, ACORPORATION OF MICHIGAN.

LAST.

Application filed April 23, 1919. Serial No. 292,140.

To all whom it may concern:

Be it known that I, VVAL'rn-n A. KnnNrLnn, a citizen of the UnitedStates, and a resident of Detroit, Michigan, have invented anImprovement in Lasts, of which the following description, in connectionwith the accompanying drawings, is a specification, like letters on thedrawings representing like parts.

My present invention relates to lasts and more particularly totwo-partlasts wherein the fore part and heel part are relativelymovable.

In. the manufacture of boots and shoes, it is most desirable to uselasts having a hinge -or jointed construction connecting the fore partand heel part and permitting them to last construction in facilitatingthe removal of the lasts from the completed shoes. Among theseobjections are the lack of rigidity in the lockingdevices to hold thelast extended; wearing of the hinge parts, looseness of the fore part onthe heel part relatively with the connecting devices; constant danger ofthe fore part and heel part being moved slightly on the pivotor hinge,

breaking the last and then when it is closed, nipping, pinching, andmarring the lining or upper of the shoe; looseness of the joint due togive and take of the wood during the drying and swelling of the last inuse, and also the expense and difficulty of assembling the usualcommercial types of hinge now in use.

The object of my present invention is to obviate all the dillicultiesabove noted and to improveand perfect the hinge type of last by astrong, simple, and inexpensive construction rendering the last easy toassemble, and so it will provide a positive, rigid,

hinge locking construction which will render the last unbreakable 1nuse, ehmmating all danger of pinching the lining, will automaticallytake up any wear or looseness in the hinge parts when locking the lastin. extended position. will easily and readily be unlocked so as topermit the last to be flexed or broken without much or any e: ertion andwhich will be very economical. In fact my present invention enables ahinge last to be locked and held locked in extended position so that itshall be as rigid as a solid or block last, entirely without wedges.separate blocks, levers, etc. but solely upon the hinge members andduring the normal operation or use of the last. In carrying out theinvention, I may use any particular line of cut and type of hinge memberwhich may be desired, preferably employing metallic hinge members fittedrespectively into the fore part and heel part and united by a pivot,with means upon one of these metallic members to be engaged by andrigidly locked with a freely movable locking ball, disc. or member,preferably capable of being housed in the other part. As a last isusually employed with the toe part upwardly and is almost always usedwith the bottom portion uppermost, I so construct the cooperating hingeand locking members with the locking ball that it will be normally heldby gravity in the locking engagement with the cooperating hinge memberwhile the last is going through the shoe manufacturing processes bottomupward and will preferably be so elty and I wish to claim the samebroadly.

As herein shown I have illustratei'l my present invention as applied tothe type of hinge last shown in my prior Patent, No. 1,094,153, issuedApril 21, 191%, to which my present invention may be readily applied.

In the type of last shown in said imtenl, for example, a very strongspring was requisite in order to hold the locking member in engagementwith the cooperating binge member and consequently in asseitnbling thelast, this spring had to be compressed and it exerted a constanttendency to loosen the hinge anchoring pins and to separate the foreparts and the heel parts of the last. This constant tension during thesuccessive breaking and extending of the last soon was apt to result ina looseness of the hinge particularly it great care was not taken 111the original assembling of the last parts and compressing the hinge. Mypresent invention by eliminating any such spring tension, reduces allstrain on the locking hinge which would in any way spread the fore partor heel aai't or loosen the anchorin iins for the hinge members, therebyinsuring longer life and usefulness to the last. One of the mostimportant features of the present last is that it is practicallyimpossible to flex or break the last while the hinge is locked, whereasformerly no matter how strong a spring was utilized, it w: possible thatit would yield and the last parts he sprung sufficiently to :atch andinjure the shoe or lining during the processes of manufacture, ordistort or spoil the shoe contour.

Referring to the drawings illustrating a preferred embodiment of theinvention Fig. 1 is a side view of my improved last with a portion ofthe woodo f both fore part and heel part broken away to more clearlyillustrate the hinge and lock, showing the hinge locked;

Fig. 2 is a fragmentary view of the last showing the heel part in flexedor broken position and with the locking member inoperative;

In the attached drawings, I have utilized a commercial type of hingewell known as the Kant Break last but it will be appreciated that othertypes of lasts having a hinge or connections, permitting movement of theheel and fore part relatively with each other may be utilized within thescope of the present invention. 7

The fore part, 1 and heel part 2 are formed with a line of cut as shown,wherein the topmost faces 3 on the fore part and 4 on the heel part,meet substantially at the curved line 5 extending around to the verticalfaces 6 on the fore part and 7 on the heel part. In the fore part isbored a recess 8 adapted to receive one of the metallic lockingmember's, herein shown as a tube 9-, which is securely anchored orattached to the fore part by a pin 10 driven therethrough. A recess orsocket 11 is formed in the heel part to receive the cooperating plate orhinge member 12, said plate being anchored to the heel part by a pin 13.These two hinge members 9 and 12 are adapted to swing on the pintle 1.5,constituting the axis for the movement of the fore part and heel partand being eoncentric with the curved face 5 in this particular type oflast. The tube 9 has slotted portions as indicated at 16 and 17 topermit the member 12 to swing above and below the line of the tube. Asthus far described the last shown in the drawings is substantiallysimilar to the type illustrated in my said prior patent. But the lockingarrangement herein is much simpler and more effective-as above brieflyexplaiiied-providing a positive rigid locle iug means and yet preferablywithout any spring or the like. On the member-12 and extending forwardlyto the "pintle 15 is formed an extension 20 having faces 21 and 22, theface 21 being formed at a slight angle relatively with the hinge member9. Cooperating with the projecting portion 20 of the hinge member 12 andadapted to roll or slide into'w'edging contact with the angular face 21of said member, is a locking ball 25 which is free to roll within thetube 9.

The operation of this locking construction is controlled by the positionand slight manipulation of the last. As above noted, lasts in' use aregenerally put through the machineoperations upside down and therefor ininverted position, from that shown in Fig. 1. .Vhen in this invertedposition, the locking ball 25 normally tends, by its weight, to rolldownwardlyinto contact with the wedge face 20 and the adjacent wall ofthe tube or member 9. Consequently to operate the last, it is simplynecessary invert the last or move the fore part 1 vertically. whereuponthelocking ball 25 will drop into engaging and locking contact, as shownin Fig. 1. \Vhen thus engaged the fore part and heel part arerigidly,firmly and positively locked and cannot readily be moved uponthe pintle 15. Furthermore anyslight iooseness which may be causedbywear, shrinkage of the wood or the last on the pins 10 and 13, orotherwise, will be automatically taken up by the locking engagement ofthe ball 25 bearing upon the wedge face 21 of said member 12 and thelast thus held firmly in closed positionwith the faces 6 and '7 closelyabutting. It is at'this point, i. e. where the'abutting faces 6 and 7join that the danger of distorting, nipping, pinching or marring thelining of a shoe during manufacture is greatestand my present inventionpositively insures the holding of these faces of a hinge last firinly incontact and, as above explained, will-so hold them even should the hingebe weak or loose. "In order to unlock or break the last, it is simplynecessary to hold the heel part upwardly and with a slight strain onthefore part 1, the locking ball 25 will'be released from its wedgingengagement and fall by its own weight downwardly out of contact and asshown in Fig. 2 would normally rest upon the forward pin 10.

It will thus be seen that my improved last combines all the advantagesof a hinge type of last together with the positive rigid lockingconstruction of a block last. Furthermore my construction automaticallycompensates for any wear orlooseness in the hinge members, alwaysholding the surface of the fore part and heel part on the last bottomclosely in contact, eliminating the wearincident to a heavy stronglocking spring and thus reducing the exertion neces sary to interlock orbreak the last, to a minimum, the slight spring 26 being of but littlepower as compared with the relatively strong springs heretofore used andconsidered necessary to hold the last in extended position.

An important characteristic of my invention consists, briefly in therigid, unbreakable. locking construction on the hinge members andpreferably by means of a gravity controlled locking member of ball 25and cooperating wedge faces. In place of the locking ball 25 and thewedge face 21 on the hinge member. I may reverse these elements so longas the same function results. i. e. I may provide the wedge far: on thelocking lnember to engage a cooperating part on the hinge member.

For this purpose. the contacting face on the hinge member, 21 in thedrawings, may be either inclined or straight relatively with the line oftravel of the loclring member. Also I consider that a light spring toactuate the sliding member into wedging engagement is a mechanicalequivalent of the gravity controlled locking ball or wedge member 25,'solong as the weight of the locking member is sufficient to compress suchspring and be released from locking engagement upon inverting the lastand releasing the wedging action by pressure on the fore part relativelywith the heel part, as above explained. Thus it will be noted that thewedging effect. presenting a positive rigid lock, and the gravityrelease of such wedging locking device constitute the fundamentalfeatures of the present hinge last. My locking member is thus controlledby gravity, and the position in which the shoe is held, and whilepreferably the ball is used, any disc. wedge, cone or other freelymovable device to. lock the last and hold it by friction or wedgingaction, capable of unlocking by gravity, is an embodiment of myinvention, and the appended claims are intended to cover all suchmodificationsa-lso the tube 9 is not essential, as any hinge members canbe employed so long as they are locked by the freely movable gravitycontrolled locking member.

My present invention is further described and defined in the form ofclaims as follows:

1. A two-part last having hinge members uniting said parts and means tolock the last in its extended position, comprising gravity controlledlocking means, said locking means being housed within one of the hingemembers.

2. A two-part last having hinge members uniting said parts and means tolock the last in its extended position, comprising a gravity controlledlocking member, engaging the hinge members connecting the last partstogether. operated to lock or unlock by in (lining the last in reversepositions respectively.

3. A two-part last having hinge members uniting said parts and means tolock the last in its extended position, con'iprising a gravitycontrolled locking member, adapted to be moved into wedging'engagementwith the hinge members and to be released from said wedging action byits weight.

4. A two-part last having hinge members uniting said parts and means tolook the last in its extended position, comprising a movable lockingmember by gravity and housed within one hinge member and adapted forpositive locking engagement with the hinge member on the other part.

A two'part last having hinge members uniting said parts and means tolock the last in its extended position, comprising a movable lockingmember housed within one part and adapted for locking engagement withthe hinge member on the other part, constructed and arranged. to bereleased from locking contact by its weight, and the position of thelast. I

6. A hinge last having a fore part. a heel part, a hinge member attachedto each part and pivoted together, one of the hinge parts extendingbeyond said pivot and having a -wedging face thereon. a movable lockingmember carried in a recess in the other part and adapted to cooperatewith a bearing surface on its part and the projecting, wedging face ofthe other hinge member, and means providing a guide for the movement ofthe locking member into and out of looking engagement by gravity.

7. A hinge last having a bored recess in one part, a hinge membersecured in said recess. a movable looking member adapted to traversesaid recess, a cooperating hinge member secured to the other last partand united to said first hinge member by a pivot, and a wedging face onthe second hinge member of appropriate form and size to cooperate withthe movable locking member, whereby a rigid, solid locking engagement iseffected by the engagement of said movable member and the locking faceof the hinge member when the last is in extended position.

8. A hinge last having a bored recess in one part, a tubular hingemember secured in said recess. a locking ball adapted to be freelymovable by gravity in. said tube and a cooperating hinge member in theother part having a ball engaging surface, whereby the two hinge memberswill be rigidly locked when the last is in extended position and theball contacts with said. wedging face.

9. A hinge last having a bored recess in one part, a tubular hingemember secured in said recess, a locking ball therein adapted to befreely movable by gravity, a plate hinge secured. in the other part, apivot uniting said hinge members, a portion on the plate hingeprojecting beyond the pivot and said tubular hinge member being slottedto permit the movement of the plate above and below said tube, and awedge face formed at a slight angle relatively with the axis of saidtube and normally extending within the tube, adapted to cooperate withthe locking ball when the last is extended and held at an inclination topermit said ball to traverse the tube hinge member, whereby rigidunbreakable locking engagement is provided on the hinge members.

10. A hinge last having a fore part, a pivot for said hinge, a heelpart, a portion of the wood of one part extending about the pivot onwhich said last part swings, a knuckle joint concentric with the pivothaving a radius sufliciently small to provide a substantiallycylindrical engagement of the last parts with each other, a spring tonormally hold said last parts in said. extended position and a gravitycontrolled locking member to hold the last parts extended, said lockingmember being housed within one of the last parts.

11 A- last, comprising a forepart and a heel part pivoted together, withprovision for relative movement to provide collaps ing and extendingaction, one last part hav ing a concealed recess and a rolling lookingmember adapted to transverse said recess to lock the last rigidly in oneof its said positions.

12. A last, comprising a forepart and a heel part pivoted together, withprovision for relative movement to provide collapsing and extendingaction, onevlasv part hay mg a concealed recess, a metallic lining insaid recess, and a rolling locking member the last in its extendedposition, comprising agravity controlled locking member, adapted to bemoved into wedping engage-- ment with the hinge members and to bereleased from said wedging action by its weight, in combination withmeans cooperating with the locking member to compensate automaticallyfor wear of said member and the parts contacting therewith.

14. A two part last having hinge mem-- bers uniting said parts and meansto loci; the last in its extended position, comprising a gravitycontrolled locking member, adapted to be moved into wedging engagementwith the hinge members and to be released from said wedging action byits weight, in combination with means cooperating with the lockingmember to compensate automatically for wear of said member and the partscontacting therewith, con sisting in wedging faces, permitting a rigidwedging action of thelockin'g member on said faces irrespectiveot wear.

In testimony whereof, I have signed my name to thisspecification," inthe presence of two subscribing witnesses. V

lVALTER A. KRENTLER.

Witnesses f V A. H, AYLns,

AUeUsTA L. RIEeEL.

